Where your data lives
Everything you enter — debt balances, interest rates, minimum payments, your extra payment
amount — is calculated locally in your browser and saved to your browser's own storage
(localStorage), under a single key, dp.scenario.v1, purely so your
session is still there if you close the tab and come back. That data never leaves your
device. There is no database, no backend, and no account system on the other end to send it
to.
Share links
When you use the "Share this plan" button, your scenario is encoded directly into the URL
itself, after the # symbol — a "fragment." Browsers never send the fragment
portion of a URL to a server; it's handled entirely client-side, so even a shared link
doesn't transmit your numbers to us or to anyone else. Anyone with the link can decode it in
their own browser, but we never see it.
Analytics
We use Vercel Web Analytics to understand aggregate traffic — things like how many people visit and which pages are popular. It's cookieless: it doesn't use cookies, doesn't fingerprint your device, and doesn't track you across sites. It never includes the financial figures you enter — those stay in your browser.
No cookies, no tracking
This site does not set tracking cookies, does not build advertising profiles, and does not share data with data brokers or ad networks. If we ever run ads (see the About page), we will not hand them any of your calculator data — ad slots on this site are just reserved space, not personalized based on what you type.
Changes
If anything here changes — a new analytics tool, a new feature that talks to a server — we'll update this page to reflect it honestly.